I have a sc300 and when im shifting into second gear it grinds(upshifting or downshifting). The clutch is fully engaged and my foot is off the gas. its worse when I shift fast or above 3500rmp even though the clutch is in. so pretty much the lower the rmp the easier it is to get into second. its a 92 SC300. 87,500miles

 

Sounds like your 2nd gear synchro may be worn. You could double clutch, both up and down, which would take some of the pressure off the synchro, but I'm afraid you're looking at a little transmission work.

What's your driving style like? I had a 93 SC (which I sold to one of my partners.......how's that for trusting my car??) with 93k, no trans problems (still none to my knowledge, probably over 100k at this point).